Unraveling the links between intracranial artery stenosis, cerebral perfusion, and white matter hyperintensity in moyamoya disease

Objectives White matter hyperintensity (WMH) is commonly observed in patients with intracranial artery stenosis (ICAS), such as atherosclerosis or moyamoya disease (MMD). However, the relationships between ICAS, cerebral blood flow (CBF), and WMH remain unclear. We aimed to investigate whether reduced CBF mediated the relationship between ICAS and WMH in MMD. Materials and methods We retrospectively analyzed prospectively collected data of patients with MMD who underwent 3T-MRI between June 2020 and July 2023. CBF in the territories of anterior cerebral artery (ACA), middle cerebral artery (MCA) and posterior cerebral artery (PCA) was quantified using arterial spin labeling, and the stage of ICAS was evaluated by MRA. We pooled the data from each hemisphere together. Results Sixty-five patients were included, with WMH mainly distributed within the MCA territory. Among 124 hemispheres with WMH, WMH volume increased with the increased stage of ICAS (p < 0.001). CBF in each arterial territory showed a negative correlation with WMH volume (ACA: r = -0.364; MCA: r = -0.406; PCA: r = -0.309; all p < 0.001). Linear mixed-effects models revealed that ICAS stage (beta = 0.132, p = 0.026) and CBF in the MCA territory (beta = -0.026, p = 0.019) were significantly associated with WMH volume. Mediation analysis showed that decreased CBF in the MCA territory mediated 40% of the effect of ICAS on WMH volume. Conclusions Hypoperfusion in the MCA territory partially mediated the association between ICAS and WMH, suggesting that enhancing perfusion could be a potential treatment strategy for WMH in MMD. [GRAPHICS]